1. Technical Field
The present disclosure relates to thin film transistor (TFT) arrays, and particularly to a mother TFT array substrate including printed wirings with bridge layer of corrosion-resistant material, and TFT array substrates fabricated therefrom.
2. Description of Related Art
Liquid crystal displays are commonly used as display devices for compact electronic apparatuses, because they not only provide good quality images but are also very thin. A liquid crystal display generally includes a liquid crystal panel. The liquid crystal panel generally includes a TFT array substrate, a color filter substrate, and a liquid crystal molecule layer disposed therebetween. In mass production of liquid crystal displays, a plurality of individual TFT array substrates may be obtained by cutting a mother TFT array substrate into separate pieces.
Referring to FIG. 5, a typical mother TFT array substrate is shown. The mother TFT array substrate 1 includes an insulating substrate 11, a plurality of TFT arrays 12, and a plurality of printed wirings 13. The plurality of TFT arrays 12 and the plurality of printed wirings 13 are formed on the insulating substrate 11. Each of the TFT arrays 12 defines a TFT array substrate 10 including a plurality of TFTs 121. The printed wirings 13 are connected between adjacent TFT array substrates 10. The mother TFT array substrate 1 can be divided into a plurality of TFT array substrates 10 along cutting lines A-A. After that, the printed wirings 13 are generally used to connect the TFTs 121 and an integrated driving circuit (not shown).
Referring to FIG. 6, each of the printed wirings 13 includes a metal layer 131 and a protective layer 132. The metal layer 131 is generally of aluminum printed on a surface of the insulating substrate 11. The protective layer 132 is generally of insulating material covering the metal layer 131, such that metal layer 131 is isolated from the environment by the protective layer 132, preventing damage thereto by moisture.
However, when the mother TFT array substrate 1 is cut into a plurality of TFT array substrates 10, each of the printed wirings 13 is broken, exposing a split. Moisture can thus easily erode the metal layer 131 through the split, and the corrosion may spread along the metal layer 131 to affect the TFTs 121.